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package java.awt.event;

import java.util.EventListener;

The listener interface for receiving hierarchy changed events. The class that is interested in processing a hierarchy changed event should implement this interface. The listener object created from that class is then registered with a Component using the Component's addHierarchyListener method. When the hierarchy to which the Component belongs changes, the hierarchyChanged method in the listener object is invoked, and the HierarchyEvent is passed to it. 
 Hierarchy events are provided for notification purposes ONLY; The AWT will automatically handle changes to the hierarchy internally so that GUI layout, displayability, and visibility work properly regardless of whether a program registers a HierarchyListener or not. 
Author:
     David Mendenhall
See Also:
HierarchyEvent
Since:
      1.3/**
 * The listener interface for receiving hierarchy changed events.
 * The class that is interested in processing a hierarchy changed event
 * should implement this interface.
 * The listener object created from that class is then registered with a
 * Component using the Component's {@code addHierarchyListener}
 * method. When the hierarchy to which the Component belongs changes, the
 * {@code hierarchyChanged} method in the listener object is invoked,
 * and the {@code HierarchyEvent} is passed to it.
 * <p>
 * Hierarchy events are provided for notification purposes ONLY;
 * The AWT will automatically handle changes to the hierarchy internally so
 * that GUI layout, displayability, and visibility work properly regardless
 * of whether a program registers a {@code HierarchyListener} or not.
 *
 * @author      David Mendenhall
 * @see         HierarchyEvent
 * @since       1.3
 */
public interface HierarchyListener extends EventListener {
    
Called when the hierarchy has been changed. To discern the actual type of change, call HierarchyEvent.getChangeFlags(). 
Params:
e – the event to be processed
See Also:
HierarchyEvent.getChangeFlags()/**
     * Called when the hierarchy has been changed. To discern the actual
     * type of change, call {@code HierarchyEvent.getChangeFlags()}.
     *
     * @param e the event to be processed
     * @see HierarchyEvent#getChangeFlags()
     */
    public void hierarchyChanged(HierarchyEvent e);
}